I agree with you, it seems very short-sighted of the CDE to block information by researchers.

“What are state officials afraid of?” Jacobs said. “That their performance in running the school system during the pandemic in fact aggravated the achievement gap? That notwithstanding their protestations, they haven’t done enough to address that problem?” (bold added by me)

I think the CDE might be afraid that there will be political fallout from the opinion I put in bold above. I think everyone can say that children at home during 2020 and 2021 didn't receive the best education they could've received at their respective schools, and it's more than likely it affected poor and minorities over white children. Yet that seems to be universal.

It's easy to blame teachers and administrators, but I think they were trying to do the best they could given the direction they received from their boards, state, and federal officials. That children received education at home during a pandemic is a phenomenal feat, given that you couldn't have done that effectively a decade ago. I firmly believe that educators and policy makers should use COVID19 as a lesson, and move on.